Street sweeper



T. F. MURPHY Nov. 1, 1966 STREET SWEEPER 5 Sheets-Sheet 1 Filed June 17,1964 MW jyc mzcas fi 9 04M {Mina T. F. MURPHY STREET SWEEPER Nov. 1,1966 5 Sheets-Sheet 2 Filed June 17, 1964 WWW Nov. 1, 1966 T. F. MURPHY3,281,879

STREET SWEEPER Filed June 17, 1964 5 Sheets-Sheet 5 T. F. MURPHY Nov. 1,1966 STREET SWEEPER 5 Sheets-Sheet 4 Filed June 17, 1964 T. F. MURPHYNov. 1, 1966 STREET SWEEPER 5 Sheets-Sheet 5 Filed June 17, 1964 UnitedStates Patent 3,281,879 STREET SWEEPER Thomas F. Murphy, 1625 TerraceRoad, Homewood, 1111. Filed time 17, 1964,Ser.No. 375,808 14 Claims.(til. 15-84) This invention relates to a novel street sweeper and moreparticularly to a four wheel street sweeper which, by reason of noveldesign features incorporated into its structure, has efliciency,flexibility and adaptability for operation under varied local street andhighway condi tions.

There are basically two types of street sweepers currently available onthe market. Both possess serious limitations. The seemingly more popularthree wheel sweepers require a chassis structure specially designed forthe task. The less popular four wheel sweeper is usually a modifiedtruck chassis, which is more economical for a starting point inconstructing a street sweeper.

In the three wheel sweeper, there is a single Wheel which steers thevehicle and paired wheels which usually support the major weight of thesweeper. Rear or front wheel steering appears to be optionaldependingupon the design. A main broom generally located near the paired wheels,sweeps the debris, kicked out by one of two gutter brooms at the frontof the vehicle, from the gutter of the street being swept, forwardly upa chute. Usually the chute is an independent continuous moving belt orother like conveyor which conveys swept debris into a hopper. Variousclutching mechanisms to operate the main broom, the gutter brooms, andthe conveyor off the main sweeper propelling motor are usually required.Because broom speeds of about 80 rpm. are optimiurn for sweeping andbecause clutching off the main motor is used to operate the broom andbecause of the basic instability of three wheel support, three wheelsweepers are generally slow operating. This is obviously undesirable forhigh speed highway cleaning and for transport of the sweeper to distantspaced sites of use. To overcome this, the trade has resorted to thefour wheel sweeper. A truck chassis is drastically modified and sweeperattachments, the main broom, the gutter brooms, the conveyor and thehopper are positioned thereon. Usually the chassis frame is cutimmediately behind the cab. Then, a rearwardly extending widerreplacement chassis frame is welded to the cut frame. This widerreplacement chassis permits support of a wide main broom and an equallywide conveyor for receiving the swept debris. To avoid being limited byoptimum broom speeds, a separate motor is positioned on the replacernentchassis to operate the main broom, the conveyor and the gutter brooms,one on each side, at the front or side of the vehicle. Even with suchseparate drive means, complicated gearing, clutching, drive shaft orchain belt propulsion devices are needed to drive all the elements andthese are relatively delicate for the environment under which the streetsweeper is used. The use of a replacement chassis bed also presents newproblems. The wider spaced rear wheels necessitated, by the width of themain broom and the conveyor, prevents adequate spring support so thatthere is frequent rear axle breakage. The need to position the hopperforwardly of the sweeper causes undesirable unloading of debris underthe chassis and tire damaging back up over the deposited debris. Indeed,the prior art four wheel sweepers are not only ungainly in appearancebut also oftentimes dangerous to operate because of the obstructed viewsof the gutter broom etc. There have been a few instances where curioussidewalk superintendents, particularly children, have been injured bysuch sweepers. One must therefore conclude that four wheel sweeperscurrently available on the market are not the complete solu- 328L879Patented Nov. 1, 1966 tion which the trade desired. Apparently each typesweeper is limited to certain sweeping operation. The optimum versatilesweeper has yet to be marketed.

An object of this invention is to provide an improved street sweeperwhich is not only efiicient in operation, but also flexible in designand adaptable to perform under Various operating conditions.

Another object is to provide a street sweeper, of the above character,which utilizes a standard stock truck chassis making it unnecessary todesign or substantially alter the prime moving element of the streetsweeper.

Still another object is to provide a street sweeper of the abovecharacter which has four Wheels so that it is easier to handle withoutdanger of upset due to off balance loads.

A further object is to provide a sweeper which is mounted on the chassisof a standard stock truck whereby an operator can easily adapted himselfto its operation since it operates in a fashion similar to any othertruck.

A still further object is to provide a street sweeper of the abovecharacter, which is particularly suited for use on high-speed roadways.

Another object is to provide a street sweeper of the above characterwith a single gutter sweeper mounted visibly to the operator, on thefront of the truck and capable of being swung to either side of thetruck so that only a single gutter broom is required.

Another object is to provide an improved street sweeper of the abovecharacter having an improved conveyor system for carrying the debris tothe hopper.

Another object is to provide an improved street sweeper, of the abovecharacter having a unique hydraulic system for driving the individualsweeper elements and for lifting those elements to enable high speedtravel between distant sites of use which is independent of the sweeperdrive means whereby the elements, may be operated at an optimum speed ofrotation.

Other objects of the invention will in part be obvious and will in partappear hereinafter.

Briefly, the street sweeper 10 of this invention comprises a standardunmodified truck body 11, upon which is mounted a single swing-typegutter broom assembly 12, a pick-up or main broom assembly 14, a uniqueconveyor means 13, a hydraulic circuit for operating and/ or lifting thegutter broom, the sweeper broom and the conveyor and a hopper 19 forstoring the debris.

The gutter broom assembly 12 is mounted on the front of the truck 11 andi adapted to be swung to either side of the truck 11, so that only asingle broom is rerequired. Furthermore, the gutter broom 20 may berotated in either a clockwise or counter-clockwise direction, and may'be lowered or raised for sweeping or for high speed travel from site tosite by the hydraulic system.

The main or pick-up broom assembly 14 is attached to the rear of thetruck 11. It has a sweeper broom 76 tranversely disposed to the truck 11for sweeping debis into the conveyor means 18. It is designed so thatthe position of the broom 76 with respect to the surface of the road isadjustable as the bristles of the broom Wear. And like the gutter broom,the main broom assembly can also be lowered or raised, as required forsweeping or transporting the street sweeper.

The gutter sweeper assembly 12 and the main broom assembly 14 are alsodesigned for easy disconnect from the truck 11 whereby replacement orrepair is facilitated.

The conveyor 18 is a unique T-shaped conveyor having transverse screws119 and 120 which feed an upwardly sloped central screw or belt or chainplow 122 whereby the debris is easily conveyed to the hopper 19. Theconveyor 18 is also arranged to be pivotal so that it and the main broomassembly 14 can be easily swung up for fast transport or disconnect fromthe truck 11 for replacement and/or repair.

The hydraulic system is independently powered and is arranged to rotatethe gutter broom 20 and the pick-up broom 76 in either a clockwise orcounter-clockwise direction and to raise and lower both the gutter broomassembly 12 and the pick-up broom assembly 14. The operation of thehydraulic system may be controlled from a central position, which may bewithin the cab of the truck 11.

The hopper 19 is designed to straddle the chassis of the truck 11 and'has doors on each side thereof so that the debris may be dumped to thesides of the truck 11. It is therefore unnecessary, as in the past, todump the debris and then to back the truck over the debris withconsequent damage to the front tires. The hopper 19 also has slopedwalls wihin its interior to direct the debris towards the doors of thehopper to facilitate its removal.

The above description is not intended to be complete in all the featuresand advantages of the various components of the street sweeper, but isintended only to briefly set forth the principal components thereof.

The invention accordingly comprises the features of construction,combinations of elements, and arrangements of parts which will beexemplified in the constructions hereinafter set forth, and the scope ofthe invention will be indicated in the claims.

For a fuller understanding of the nature and objects of the invention,reference should be had to the following detailed description taken inconnection with the accompanying drawings, in which:

FIG. 1 is a side view of an embodiment of the street sweeper of thisinvention;

FIG. 2 is a top view;

FIG. 3 is a front view;

FIG. 4 is a side view of the gutter broom assembly;

FIG. 5 is a partial sectional view of said gutter broom assembly, takenalong the lines 55 of FIG. 4;

FIG. 6 is another partial sectional view of the gutter broom assemblytaken along lines 6-6 of FIG. 4;

FIG. 7 is a rear view of the street sweeper showing the pick-up or mainbroom assembly;

FIG. 8 is a side detailed view of the pick-up broom assembly;

FIG. 9 is a partial perspective view of the pick-up broom assemblyillustrating the skid arrangement used for guiding the debris as it isswept by the main broom;

FIG. 10 is a partial perspective view illustrating the pick-up linkagefor the pick-up broom assembly;

FIG. 11 is a partial top view illustrating the conveyor of the streetsweeper;

FIG. 12 is a partial sectional view of the conveyor, taken along line12--12 of FIG. 11.

FIG. 13 is a top plan view of an alternate pick-up broom arrangement;and

FIG. 14 is a schematic block diagram of the hydraulic system used withthe street sweeper shown.

Similar reference characters refer to similar parts throughout theseveral views of the drawings.

Referring now to the drawings, a street sweeper 10 exemplary of thepresent invention is shown including a truck 11 equipped with a cab andthe means for motivating the same, such as a motor, transmission, etc.,the details of which are well-known in the art. The street sweeper 10 isdesigned and constructed so that the truck 11 can be of any standardproduction type of sufficient size to support and transport theindividual components hereinafter described, and the novelty andadvantages of such arrangement will be apparent from the descriptionwhich follows.

A gutter broom assembly 12 is mounted on the front bumper 21 or the likeof truck 11 and is positioned such that the driver may have it in hissight while driving the street sweeper 10, rather than being mounted onthe side and to the rear of the street sweeper, as in the majority ofthe prior art arrangements, which position required the driver toalternate between watching the path of travel of the street sweeper orthe gutter broom. This arrangement therefore is considerably safer thanthose of the prior art, and is also more convenient since the driver canalways keep it in his sight.

The gutter broom assembly 12 is pivotally connected and is arranged tobe shifted from one side to the other of the street sweeper 10 so thatonly one gutter broom assembly is required.

The pivotal connection with the truck 11 is provided by an attachmentassembly 22 formed of the two horizontally extending bumper bars 13 towhich are connected in spaced relation, in positions hereinafterdescribed, a pair of spaced T-shaped gutter broom support brackets 54formed of two angle bars with pins 52 between them and a U-shaped gutterbroom rpivot bracket 24. Bracket 24 is centrally located on the bumperbars 13 between the pair of T-shaped brackets. The attachment assembly22 can be constructed as a unit and can therefore be easily andconveniently secured to the truck 11, by means of nuts and bolts or bywelding.

The arms 26 of gutter broom bracket 22 extend outwardly from the bumper21 substantially parallel with the surface of the street. The arms 26each have an aperture (not shown) therein for receiving the pivotalsockets 28 attached to the ends of the support arms 31 and 32respectively. The pivotal sockets 28 are of the type which allow thesupport arms 31 and 32 to pivot both vertically and horizontally, aswell as in both directions simultaneously.

The pivotal sockets 28 are fixedly secured within the apertures in thearms 26 by' means of threaded nuts. Therefore the gutter broomattachment 112 can be easily connected to and removed from the truck 11by merely removing these nuts and by disconnecting the hydraulic lines29 and 30, which may include quick disconnect couplers.

The support arms 31 and 32 extend horizontally from the pivotal sockets28 and are secured in parallel relation by means of a transverselypositioned spanner bracket 34, the support arms 31 and 32 and thebracket 34 each having apertures therein for receiving bolts 36 and 37.Secured to spanner bracket 34 is a platform 40 which supports gutterbroom drive hydraulic motor 41, and a bearing retaining member 38 whichreceives and retains the drive shaft 39 of the gutter broom 20, thedrive shaft 39 being coupled to the hydraulic motor 41.

The support arms 31 and 32 are secured between a pair of uprightsupports 42 and 43 (see FIGS. 4 and 6) and are arranged to belongitudinally moved therebetween for adjusting the horizontal positionof the gutter broom 20, by means of gutter broom positioning spring 47and gutter broom hydraulic cylinder 56.

Gutter broom positioning spring 47 is connected, at its lower end, tothe support arm 31 and at its upper end to a threaded shaft 46, which isthreadably received within an extending plate 44 secured to the top ofthe upright supports 42 and 43. The shaft 46 has a handle 48 secured toits upper end, for adjusting the tensional force of the spring 47, in amanner and for reasons explained in greater detail below.

The hydraulic cylinder 56 is pivotally secured at its lower end to thesupport arm 31 and at its upper end to an extending bracket connected tothe top of the support arms 42 and 43.

At the lower end of support arms 42 and 43 are locking plates 49 and 51,respectively, which have locking slots 51 formed therein that extendinwardly from their outer edges in an upwardly angled direction, andwhich are arranged to engage pins 52 of the T-shaped gutter broomsupport 54.

In use, the gutter broom sweeper attachment 12 is positioned to one sideor the other of the street sweeper 10, with the pins 52 of thecorresponding bracket 54 slidably received in the locking slots 51 inthe locking plate 49 or 50. The spring 47 is adjusted, by rotating thehandle 43 in either a clockwise or counter-clockwise direction, to exerta downwardly directed force on the support arm 31, which force iseffective to both retain the pins 52 in the slots Sit and to constantlyurge the gutter broom 20 against the surface of the street. It may benoted that the support arms 31 and 32, being secured in parallel, retainthe sweeping surface of the gutter broom 20 in the same angular positionWith respect to the surface of the street, as the gutter broom 20follows the surface contour.

Lower support arm 32 has a shock absorb shaft 60 connected to its frontend which slidably receives a spanner connecting bar 61 secured to thespanner bracket 34. Retained between the connecting member 61 and thelower support arm end 32 is a shock absorb spring 62 which uniquelyfunctions to maintain the gutter broom 20 in the same angular positionwith respect to the surface of the street and also to absorb the shocksexerted on the support structure by the gutter broom 26 being rammedagainst a curb or the like.

In operation, the gutter broom attachment 112 is positioned to one sideor the other of the street sweeper 10, in the manner described above,and the gutter broom rotated in a clockwise or counter-clockwisedirection depending on the position of the gutter broom attachment 12 bymeans of the hydraulic motor 41 which is activated by the main hydraulicsystem. The gutter broom 20 is maintained or urged against the surfaceof the street by means of the spring 47 and against the gutter or curbby means of the spring 62, so that the gutter broom follows the surfacecontour of the street and of the curb, Within the limits defined by themaximum expansion of the springs 47 and 62.

The gutter broom 20 is shifted to the opposite side of the streetsweeper it by activating the hydraulic cylinder 56 to raise the gutterbroom 20 above the surface of the street. A force is then manuallyexerted upwardly upon the support arms 31 and 32, which force will beeffective to disengage pins 52 from the locking notches 51 formed in oneof the locking plates 49 or 50. The entire assembly is then pivotedabout the gutter broom pivot bracket 24 until the other locking plate 49or 50, as the case may be, engages the other T-shaped gutter broomsupport bracket 54 on the opposite side of the street sweeper l0, and adownward force is again exerted on the support arms 31 and 32 toslidably engage pins 52 in locking notches 51. The hydraulic cylinder 56is then actuated to lower the gutter broom 20 to contact the surface ofthe street. It should be evident, from this description that the gutterbroom 20 may be switched in minutes from one side to the other of thestreet sweeper in a very simple and convenient manner.

The gutter broom sweeps the debris from the gutter to .a positionbetween the wheels of the truck Ill, as should be evident from FIGS. 1and 2. The pick-up or main broom at the rear of the truck lll, thensweeps up the debris and deposits it in the hopper.

As seen in FIGS. 1, 2, 8 and 10, the pick-up or main broom assembly orattachment 14 comprises a horizontally disposed U-shaped broom supportframe 65 with two rearwardly extending arms 63 and 64. Frame 65, isconnected to the truck Ill by means of a trailer hitch (see FIG. 1)1118.

Each rear end of each arm 63 and 64 connects to an angularly positionedbroom axle take-up frame 72 which acts as the journal for the broomaxle. Since each frame is similar in structure, only one will bedescribed in detail hereinafter.

Slidably received within frame 72 is a journal block 76 which receivesand retains the end of main broom axle 77.

Bolt 74, threaded to the frame 72, with lock-nut '75 permits positioningand locking of the pick-up broom 76 with respect to the street beingswept.

A forwardly extending broom arm securement tube 67, preferably square tofit the cross-sectional configuration of arm 64, and welded to frame 72,secures the frame on the arm. It is retained there, in an easilyremovable but firm manner, by pin 66 which fits through an orificeextending through the tube and the arm. It should be evident that thissecurement means facilitates any removal of the main broom for repair orreplacement. The mere removal of pin 66 enables rearward displacement ofthe main broom with respect to broom support frame 65. Then by outwarddisplacement of broom end plates 78, a single operator can very easilyreplace the broom.

The large, substantially circular-shaped broom end plate 78, secured tobearing housing 72 prevents debris which is swept up by the pick-upbroom 76 from being blown outwardly of the broom. It also functions tosupport the broom at a certain distance from the street surface with thehelp of a wheel assembly 79 and a skid 80.

As shown, best in FIG. 8, wheel assembly 79 is adjustably secured toplate 78 via pivot 85, and screws 82, within angular slots 81. Wheelassembly leveling bolt 84 threadably journaled within block 86 of theplate 78, and lock nut 88, enables simplified positioning of the pick-upbroom with respect to the surface of the street.

As seen in FIG. 9, main broom skid comprises a horizontally positionedangle iron with upturned ends which allow them to follow or ride overobstructions on the surface of the street. It is movably secured to theplate 78 by bolts 89 which extend through elongated apertures 90, sothat skid 80 may freely ride up and down in accord with the contour ofthe street.

Just forward of plate 78 and secured to each arm 63 is a verticallydisposed plate 83, which has a channelshaped member 91 angularly securedthereto for slidably receiving a forward removable main broom cover 92.The cover 92 spans across the entire width of the broom 76 and issimilarly secured to arm 69 at its far end. It prevents debris sweep upby the pick-up broom 76 from being thrown over its top.

As seen in FIGS. 2 and 7, a hydraulic motor 99 is secured to one broomaxle take-up frame 72 and is coupled to the axle 77 for rotating thebroom, in either a clockwise or counter-clockwise direction. Usually thebroom is rotated to sweep debris forwardly. The hydraulic motor 99 isactivated and controlled through the main hydraulic system, in a mannerhereinafter described.

Debris swept forwardly by the pick-up broom 76 is directed, by themechanism described, into a transversely positioned trough 16 (see FIGS.1 and 11). A pick-up apron 96, is affixed to the rear end of trough 16and extends rearwardly and underneath the front of the pick-up broom'76. Apron 96 is secured to trough 16 by a piano hinge 98. It ispreferably made of rubber or similar flexible material.

It may be noted from FIG. 1, that the U-shaped channel member 65 and thetwo arm members 63 and 64 are arranged to lie in a substantiallyhorizontal plane parallel to the surface of the street. The pick-upbroom 76 is secured within the channel member 65. With such anarrangement, positive control can be had over the horizontal positioningof the pick-up broom 76 and this extends its life. This is of greatadvantage because such brooms are relatively expensive. In the prior artthe life of pick-up brooms were relatively short because they weresuspended in brushing relationship with the surface of the street bymeans of springs or the like. With such prior structures, up and downbouncing or side to side rocking frequently occurred to cause the highlyundesirable uneven wear of the bristles. If shock absorbers or the likewere provided to prevent such bouncing or rocking, bristle or broombreakage frequently occurred.

Now, with the structure described, the broom is lightly urged againstthe surface of the street, so that a continuous, rather than a spotted,path is swept. Even more important is that the pick-up broom isprotected against uneven wear and from damage caused by strikingobstructions or ruts in the street surface. Wheel assembly 79 and skid30 are highly instrumental in .such protection of the broom. Indeed,with proper positioning of the wheel assembly 79 and skid 80, one couldalmost use an unevenly worn broom and make it even. The benefits derivedfrom the main broom structure now discovered are almost limitless.

For transport of the entire street sweeper to distant sites of use, thepick-up broom attachment 14 can be raised above the street surface whilethe sweeper is being driven over the highway. Such raising isaccomplished by the linkage assembly 100, which may be best seen in FIG.10. The linkage assembly 100 includes a pair of turnbuckles 101 and 102,the lower ends of which are pivotally secured to arms 64 and 63 bystirrups 104 and 105 respectively. The upper end of the turnbuckles arepivotally secured to lever arms 106 and 107, respectively which, inturn, are rigidly secured to the ends of a main broom lift shaft 108.The lift shaft 108 is rotatably secured within brackets 114 (see FIG. 2)which are rigidly secured to the end of the truck chassis 116. Lift arm109 secured to shaft 108 and pivotally retained within forked piston rod111 of a hydraulic cylinder 112 enables complete lifting of the entiremain broom assembly. To raise the pick-up broom assembly 14, the sweeperoperator merely activates hydraulic cylinder 112 through the mainhydraulic system to draw piston 111 forwardly (as seen in FIG; 10). Thiscauses the shaft 108 to rotate in a counter-clockwise direction withinbrackets 114. The arms 106 and 107 are therefore rotated in acounterclockwise direction to lift broom support member 65, thus raisingthe pick-up broom 76. To lower the pick-up broom 14, a reverse operationis instituted.

Now describing the conveyor 18 in detail, trough 16 is transverselypositioned to face the pick-up broom 76. It contains two rotatable feedscrews 119 and 120 which carry the debris swept into the trough 16 to alift trough 121, angularly positioned over and partly through the backof the truck chassis.

In the prior art sweepers, the conveyor was generally a broom-wide beltarranged to span across the entire width of the pick-up broom 76. Withthis arrangement it was impossible to easily change broom widths for asimilar change in the belt was also required. More detrimental however,to good street sweeper design, was the fact that the wide broom-beltarrangement required a wide rearwheel support structure. Thus, the needfor a replacement chassis in the four-wheel sweeper should becomeevident. The ordinary truck chassis would not permit the use of asatisfactorily wide main broom or belt. So the trade resorted to thereplacement chassis.

Unfortunately, the replacement chassis, because of its width, because ofstructural requirements for the street sweeper and because of theoperating needs of the main broom elements, prevented adequate springsupport for the axle and wheels of said chassis. Frequent axle breakageoccurred. The operator, in ferrying the sweeper from site to site had tobe extremely cautious not to drive over ruts etc. in the street orhighway.

Frequent axle breakage also occurred because of the axles inability toprovide the slight counter-reacting torque which is needed when trucksare started in forward motion, or are rapidly accelerated.

Within lift trough 121, are two endless lift chains 123 and 124 whichhave plows 122 spaced at intervals along the length thereof, forcarrying the debris to the hopper 19. Chain 123 runs over sprockets 125and 126, while chain 124 runs over sprockets 127 and 128. Sprockets 125and 127 are secured to shaft 129 disposed within the hopper 19 whilesprockets 126 and 128 are secured to the common shaft 130 which rotatesthe two screw conveyors 119 and 120. The latter are therefore driven bythe same hydraulic motor as the chains 123 and 124 and this providesbetter control over the entire conveyor. It should be evident that withthis arrangement the speed of the conveyor may be varied in accordancewih the needs of the situation. Also the preferred use of a hydraulicmotor to power the conveyor prevents damage or burn-out of the motor.Should some clogging of the conveyor plow chain or feed screws occur byreason of a large piece of debris, the motor merely stalls.

It should also be evident that the chain plow could be replaced by abelt or by an auger enclosed within the lift trough.

Another advantage of the conveyor arrangement of the present inventionis the ease with which the street sweeper 10 may be modified to sweep awider surface, such as an airport runway. It is merely necessary toremove the end walls 131 and 132, which are removably secured to trough16 by screws 133 and either replace or extend feed screws 119 and withlarger feed screws or with extension screws to said feed screw. Screws119 and 120 are telescopically received on shaft and secured thereon bybolts 134 or cotter pins or the like, and therefore may be easilyreplaced with lengthier feed screws. Trough extensions (not shown)designed to be addable onto the ends of trough 16 must also be used. Apick-up broom attachment having a correspondingly larger pick-up broomis also necessary for such enlargement of sweeping surface.

The lift trough 121 may be open, however, it is preferred that it 'beenclosed, to prevent debris from blowing out of it as the street sweeperis moving, and a top 135 is provided for enclosing the same.

The lift trough 121 terminates within hopper 19, which is straddlemounted on the chassis of the truck 11. The hopper 19 has doors, such asdoor 136, disposed on the lower end of each of its sides so that it maybe emptied to the sides of the street sweeper 10. This avoids the priorart necessity of backing the street sweeper over the deposited debris.

Hopper 19 consists of a flat top wall 146 having a closed lift chainobservation manhole 146a therein (see FIGS. 1 and 2). Four side walls201, 202, 203 and 204 depend from the top wall 146, so that it is aclosed construction, with the flight conveyor being passed through rearside wall thereof and arranged with an opening in its bottom wallthrough which the debris drops into the hopper 19.

The bottom comprises a pair of plates 137 and 138, angularly positioned(see FIG. 12) to straddle the truck chassis and to provide two inclineswhich are sloped in opposite direct-ions to direct the debris in thehopper to the doors 136 (see FIG. 1) on the sides of the hopper 19. Theslope and position of the apex of these plates 137 and 138 not onlyfacilitate emptying the hopper 19 but also help to equalize the loaddistribution in the hopper 19.

Each door 136 vertically slides within angle flanges 140 and 142 securedto opposite side edges of the hopper. Flange 141 seals the bottom of thedoor.

Door lift hydraulic cylinder 143, secured at 144 to the hopper 19 andits piston 145 secured to the top portion of door 136 provides theopening means for the door. The control for the hydraulic cylinder maybe located within the cab of the truck so that remote control at acentral location is possible.

With respect to the hydraulic system of the street sweeper 10, it isshown schematically in FIG. 14. It includes a hydraulic multisectionpump driven prefer-ably by an independent gasoline engine 169 (see alsoFIG. 1) or a power take off drive from the transmission or fly wheel ofthe truck 11 or a direct drive from the engine of the truck 11. Anindependent gasoline engine 169 for the driving of pump 170 is preferredbecause rotation of the various sweeper brooms and the speed of theconveyor system can be maintained at a constant speed, regardless of thespeed of the truck 11 or the engine of the truck 11. Thus, the truck 11may be driven at various speeds, depending on the street trafiic, theamount of debris in the path of the street sweeper etc, and therotational speed of the sweeper brooms maintained at the optimum speedfor sweeping.

The several hydraulic motors 41, 9 and 115 for operating the brooms areconnected through four-way valves 171 to 173, respectively, to themultisection pump 170. Adjustable flow regulating valves 174 to 176 areconnected, as by-passes across each supply line to each hydraulic motor4 1, 99 or 115, respectively, to adjust the speed of the motor.

Flow equalizing valves 177 to 179 are also connected across the supplyline to each hydraulic motor 41, 99 or 115, respectively, to initiallyequalize the flow of fluid supplied to each motor and to establish amaximum speed of rotation therefor.

The four-way valves 171 to 173 and the adjustable flow regulating valves174 to 176 are preferably mounted on a control panel (not shown) ormounted in the cab of the truck 11.

The hydraulic cylinders 56, 112 and 143 used to raise and lower thegutter broom attachment 12, the pick-up broom attachment 14 and thedoors 13d of the hopper 19, respectively, are hydraulically poweredthrough the hydraulic power steering system (not shown) of the truck 11.For this purpose, a diversion valve (not shown) is connected to thehydraulic system and it diverts a portion of the output to the powersteering unit to control valves which control the operation of one ofthe above-mentioned units. These control valves may be located on thesame control panel with the valves 171 to 173 and the adjustable fiowregulating valves 174 to 176.

With such a power steering diversion arrangement, the sweeper units andthe hopper doors may be operated when the truck engine is running,without resort to the power of gasoline engine 169. It should beapparent that the main hydraulic system could be modified to alsocontrol cylinders 56, 112 and 143 but experience has shown that thepower steering diversion approach is better.

A supply of oil for the hydraulic system is maintained in tank 220,located just above pump 170 (see FIGS. 1 and 7).

To keep down dust during sweeping, the chassis also has a water tank 221which feeds a spray bar 222 attached to the bumper of the truck. The bar222 sprays water forwardly to wet and Wash down any dust caused bygutter broom 20.

In FIG. 13, there is shown an alternated pick-up broom design. Thisdesign utilizes a pair of angularly disposed pick-up brooms 150 and 151in place of the singular pick-up broom 76 to aid in directing the debrisup the conveyor. With this arrangement, the frame members 63 and 64 mustbe angled outwardly and a frame member 153 must be secured between thesame to add rigidity to the structure and to support a gear box 155positioned between the pick-up brooms 150 and 151 to receive the broomaxles 152 and 154. Gear box 155 may also be used to drive the pick-upbroom 150 and 151 by positioning hydraulic motor adjacent the box.

The pick-up brooms 150 and 151 are arranged to overlap in the center anda guide plate 156 is arranged to keep the overlapping brooms 150 and 151from becoming meshed with each other.

One of the advantages of the broom design shown in FIG. 13 is that iteliminates the need for skids 80 which prevent the debris from flowingaround the ends of the singular pick-up broom.

It will thus be seen that the objects set forth above, among those madeapparent from the preceding description, are efficiently attained and,since certain changes may be made in the above construction withoutdeparting from the scope of the invention, it is intended that allmatter contained in the above description or shown in the accompanyingdrawings shall be interpreted as illustrative and not in a limitingsense.

It is also to be understood that the following claims are intended tocover all of the generic and specific features of the invention hereindescribed, and all statements of the scope of the invention, which, as amatter of language, might be said to fall therebetween.

Now that the invention has been described, what is claimed as new anddesired to be secured by Letters Patent is:

1. A street sweeper comprising, in combination: a motorized chassis fortransporting said street sweeper, said chassis having a hopper mountedthereon for storing debris and the like, a conveyor mounted on saidchassis for conveying debris and the like to said hopper, a pickup broomassembly for sweeping debris and the like into said conveyor, saidpickup broom assembly comprising a broom having an axle, a substantiallyU-shaped trailerlike frame connected to said vehicle and having a pairof arms which extend rearwardly of said vehicle, axle support means onthe end of said arms for receiving and retaining the axle of said broom,and means for operating said conveyor system and said pickup broom.

2. The street sweeper of claim 1 having, in addition, at least onegutter broom mounted on said chassis for sweeping the gutter of thestreet.

3. The street sweeper of claim 1 wherein said conveyor comprises anaxially aligned debris lift means and transverse feed screw meanspositioned transversely on the lower end of said lift means and arrangedto convey debris and the like thereto.

4. The street sweeper of claim 3 wherein said pair of transverse feedscrews have means thereon wherein said screws may be replaced withlarger screws and wherein said pickup broom has means thereon whereinsaid broom may be replaced with a wire broom so that greater widths maybe swept by said street sweeper.

5. The street sweeper of claim 3 wherein said lift means comprises apair of endless chains in spaced relation having a plurality of plowsconnected transversely thereto at spaced intervals, spaced pairs ofsprocket means for said pair of endless chains, the first pair of whichare connected to a common drive shaft rotatably secured to said hopperand the second pair of which are connected to a shaft common to saidfeed screws and drive means connected to said drive shaft.

6. The street sweeper of claim 1 having in addition a gutter broompivotally connected on the front of said vehicle and arranged to beshifted from one side to the other of said vehicle for sweeping debrisfrom a gutter into the path of said pickup broom.

7. The street sweeper of claim 1 wherein said means for operating saidconveyor system and said pickup sweeper broom comprises a hydraulicmotor means and a hydraulic system for driving said motor means, saidhydraulic system comprising a hydraulic pump having connections withsaid hydraulic motor means and independent drive means for saidhydraulic pump.

8. The street sweeper of claim 7, wherein said bydraulic pump is amultisection hydraulic pump having supply lines coupled to each of saidhydraulic motor means, and wherein said hydraulic system furthercomprises valve means connected in each of said supply lines forcontrolling the operation and the speed of said hydraulic motor means,respectively.

9. A street sweeper comprising, in combination: a motorized chassis fortransporting said street sweeper, said chassis having a hopper mountedthereon for storing debris and the like, a conveyor mounted on saidchassis for conveying debris and the like to said hopper; a pickup broomassembly for sweeping debris and the like into said conveyor, saidpick-up broom assembly comprising a broom having an axle; asubstantially U-shaped trailerlike frame connected to said vehicle andhaving a pair of arms which extend rearwardly of said vehicle; axlesupport means on the end of said arms for receiving and retaining theaxle of said broom, said support means being adjustable for adjustingthe longitudinal positioning of said pick-up broom; and means secured tosaid frame for supporting and for adjusting the position of said pick-upbroom attachment with respect to the surface of a street; and means foroperating said conveyor system and said pick-up sweeper broom.

10. The street sweeper of claim 9, further including linkage meanspivotally connected at one end to said chassis and at their other end tosaid U-shaped frame, and means to pivot said linkage means, to therebyraise and lower said pick-up broom assembly.

11. The street sweeper of claim 9 wherein said axle support meanscomprises a frame member removably secured to each of said arms of saidtrailer-like frame,

said frame member having axial retaining structures angularly connectedthereto, axial support means for receiving and retaining said axle ofsaid pickup broom adjustably supported by each of said axial retainingstructures for adjusting the vertical positioning of said pickup broom,plate means secured to each of said frame members adjacent said pickupbroom, support means adjustably secured to said plate means forsupporting said pickup broom attachment in a fixed position with respectto the surface of the street, and skid means self-adjustably secured toeach of said plate means and arranged to slide along the surface of thestreet.

12. The street sweeper of claim 1 wherein said arms have shock-absorbingmeans connected thereto for protecting the broom from damage.

13. A street sweeper comprising, in combination: a motorized chassis fortransporting said street sweeper, said chassis having a hopper mountedthereon for storing debris and the like; a conveyor mounted on saidchassis for conveying debris and the like to said hopper; a pickup broomassembly for sweeping debris and the like into said conveyor, saidpick-up broom assembly comprising a broom having an axle; asubstantially U-shaped trailerlike frame attached to said vehicle andhaving a pair of arms which extend rearwardly of said vehicle, a framemember removably secured to each of said arms having a take-up fromeangularly connected thereto, said frame having broom axle support meanswhich are adjustably supported for adjusting the longitudinalpositioning of said pick-up broom; a plate secured to each of said armsadjacent said pick-up broom; support means adjustably secured to each ofsaid plates for supporting said pick-up broom in a fixed position withrespect to the surface of a street; and skid means self-adjustablysecured to each of said plates and arranged to slide along the surfaceof 12 the street; and means for operating said conveyor and said pick-upbroom.

14. A street sweeper comprising, in combination: a motorized chassis fortransporting said street sweeper, said chassis having four wheels, and aspring suspension arrangement; a hopper mounted on said chassis forstoring debris and the like, a conveyor system for conveying debris andthe like to said hopper, said conveyor system comprising an axiallyaligned conveyor portion mounted between said chassis and a transverseconveyor portion connected to one end thereof and arranged to carrydebris and the like thereto; a pick-up broom attachment connected tosaid vehicle having two angularly disposed pick-up brooms arranged tosweep debris and the like into said transverse conveyor portion, each ofsaid pickup brooms having an axle, a substantially U-shaped frameconnected to said vehicle having a pair of arms which extend rearwardlyof said vehicle, a frame member removably secured to each of said armseach having axle retaining structure angularl connected thereto, axlesupport means for receiving and retaining said axle of said pick-upbroom adjustably supported by each of said axle retaining structures foradjusting the longitudinal position of said pick-up brooms, plate meanssecured to said U-shaped frame and disposed between said pick-up brooms,gear means secured to said plate means and receiving said axles, supportmeans for supporting said pick-up broom attachment in a fixed positionwith respect to the surface of a street, and driving means coupled tosaid conveyor system and to said axle of at least one of said pick-upbrooms for driving said conveyor system and said pick-up brooms.

References Cited by the Examiner UNITED STATES PATENTS 542,571 7/1895Reynolds 15-83 1,176,408 3/1916 Skrzyszewski 15-340 X 1,452,307 4/1923Martin 15-87 1,454,884 5/1923 Donkers 15-83 1,585,768 5/1926 Clayton etal. 15-83 1,904,881 4/1935 Presbrey 15-82 2,641,356 6/1953 Hunter et al.198-217 2,917,761 12/1959 Burgdorlf 15-84 2,978,097 4/1961 Blanshine198-217 2,996,742 8/1961 Ainers 15-87 3,011,193 12/1961 Schmidt et al15-87 3,114,923 12/1963 Jones 15-82 FOREIGN PATENTS 415,860 9/1934 GreatBritain.

CHARLES A. WILLMUTH, Primary Examiner. S. E. BECK, Assistant Examiner.

1. A STREET SWEEPER COMPRISING, IN COMBINATION: A MOTORIZED CHASSIS FORTRANSPORTING SAID STREET SWEEPER, SAID CHASSIS HAVING A HOPPER MOUNTEDTHEREON FOR STORING DEBRIS AND THE LIKE, A CONVEYOR MOUNTED ON SAIDCHASSIS FOR CONVEYING DEBRIS AND THE LIKE TO SAID HOPPER, A PICKUP BROOMASSEMBLY FOR SWEEPING DEBRIS AND THE LIKE INTO SAID CONVEYOR, AND PICKUPBROOM ASSEMBLY COMPRISING A BROOM HAVING AN AXLE, A SUBSTANTIALLYU-SHAPED TRAILERLIKE FRAME CONNECTED TO SAID VEHICLE AND HAVING A PAIROF ARMS WHICH EXTEND REARWARDLY OF SAID VEHICLE, AXLE SUPPORT MEANS ONTHE END OF SAID ARMS FOR RECEIVING AND RETAINING THE AXLE OF SAID BROOM,AND MEANS FOR OPERATING SAID CONVEYOR SYSTEM AND SAID PICKUP BROOM.